How Much Exercise is Effective?One hour of walking at a 2 to 3 mph pace lowers your risk a little. Three to five hours weekly of brisk walking gives you the most protection from breast cancer. You could vary that by switching activities -- try jogging, hiking, swimming, cycling, or other activities that get you moving. Dr. Michelle Holmes reports in her research that breast cancer survivors who spent 3 to 5 hours each week (or about half an hour a day) doing exercise had the best survival rates. And for prevention of breast cancer recurrence, the American Cancer Society recommends that you exercise for 30 to 45 minutes at least five days each week.
Here's How Exercise Reduces Your RiskRegular exercise and a diet that is low in fat and high in fruits and vegetables lowers your levels of estradiol and estrone, two kinds of estrogen. Although women need estrogen to mature and to create strong bones, overexposure to estrogen can lead to breast cancer. Eighty percent of all breast cancers are fueled by estrogen. Exercise is a natural way to reduce your estrogen levels, as well as reducing other hormones and growth factors that can cause breast cells to turn into cancer.
Being Sedentary Increases Your RiskPhysical inactivity may contribute to the rise in several types of cancer -- colon cancer, postmenopausal breast cancer, endometrial cancer, kidney cancer, and cancer of the esophagus. Women who are overweight produce and store more estrogen in their bodies than women who have a healthy lower body mass index (BMI). Increased exposure to estrogen and risk of breast cancer are linked, since the estrogen-receptor positive kind is the most common type of breast cancer. Obese women have a greater amount of breast tissue, and it is more difficult to detect breast tumors in obese women, as compared to lean women. This can lead to detection at a more advanced stage of cancer, when it's harder to treat.
Every Body Will BenefitStudies showed that breast cancer survivors of any age or menopausal status can reduce their risk of recurrence and improve their survival rates. Women who had estrogen-receptor positive breast cancer experienced the most benefit from exercise, because exercise lowered their estrogen levels naturally. But women who had hormone-receptor negative breast cancer also benefited from exercise, when it was paired with a diet high in fruits and vegetables. A study published in the Journal of Clinical Oncology reported that exercise reduced mortality from all causes in breast cancer survivors by 50%, when combined with a healthy diet. These results were true for lean and obese women, although obese women had more trouble sticking to a healthy diet.
Other Benefits Of ExerciseLowering your risk of breast cancer is just one benefit of doing regular exercise. It also improves mood, raises your self-esteem, and gives you a better body image. Doing your exercise improves muscle tone, strength, and endurance. Exercise protects you by lowering your risk of heart disease and diabetes. It can help you lower your weight, which in turn, reduces risk of breast cancer due to obesity.
Bottom Line on Exercise and Breast CancerWhether you're trying to prevent breast cancer or recover from treatment, exercise extends your survival. Regular exercise and a healthy diet improve your overall health and boast psychological benefits as well. Find an exercise activity or program that you can stick with, or visit your local gym and take a class -- this is your chance to take that belly dancing class or learn Zumba. Commit to maintaining and improving your health to reduce your risk of breast cancer.
American Cancer Society. Exercise Can Improve Breast Cancer Survival. Updated: 2005/05/25.
Journal of the American Medical Association (Vol. 293, No. 20: 2479-2486). Michelle Holmes, MD, Harvard Medical School and Brigham and Women's Hospital in Boston.
Journal of Clinical Oncology, Vol 25, No 17 (June 10), 2007: pp. 2345-2351. John P. Pierce, et al. Greater Survival After Breast Cancer in Physically Active Women With High Vegetable-Fruit Intake Regardless of Obesity.
Journal of Clinical Oncology, Vol 25, No 17 (June 10), 2007: pp. 2335-2337. Rachel Ballard-Barbash. Is the Whole Larger Than the Sum of the Parts? The Promise of Combining Physical Activity and Diet to Improve Cancer Outcomes.